Dart Den

Well, I kinda went a little crazy on cultures preparing for my first froglets, which came today. I have four spotted auratus froglets. As for cultures: 1 springtail culture, 1 rice flour beetle culture, 2 d. hydel cultures, 5 d. melanogaster cultures, and an unlimited supply of pinheads (I work at petsmart). Now for my noobish question: Why is the yeast needed? I'm going to start making my own media to keep the fly cultures going and don't really want to store yeast...I use to use it with DIY co2 for my fish tanks, but it goes bad really fast even when kept in the fridge. So, for only using a couple grains per media a lot will be wasted which is why I ask my question.

Here is a pic of one of my hungry little froglets:

The yeast when introduced to the media starts to produce a sugar alcohol which is what the flies actually eat. So thats about it.

Thank you for clearing that up for me. I suppose I will just try and buy in the smallest quantity I can.

I just buy the little packets at the store and I keep them sealed in a ziploc and I use them all up. Despite what people are saying that they get stale fast may be true but I have used the same packet until it is gone with no noticable loss in numbers produced by the flies.

Once you open the yeast you should refrigerate it too

What is the downside to not using yeast at all? I've been breeding flies in media with no yeast and haven't noticed any problems or lack of flies being produced. Is there a negative to not using it?
Thanks!
Mike